Optimistically Terminating Consensus

Piotr Zieliński

June 2006, 35 pages

Abstract

Optimistically Terminating Consensus (OTC) is a variant of Consensus
that decides if all correct processes propose the same value. It is
surprisingly easy to implement: processes broadcast their proposals and
decide if sufficiently many processes report the same proposal. This
paper shows an OTC-based framework which can reconstruct all major
asynchronous Consensus algorithms, even in Byzantine settings, with no
overhead in latency or the required number of processes. This result
does not only deepen our understanding of Consensus, but also reduces
the problem of designing new, modular distributed agreement protocols to
choosing the parameters of OTC.